The invention relates to a closure for a container such as a cap for a bottle or the like.
Bottle stoppers are injection molded by many various methods. EP Patent No. 0 056 469 describes single-piece stoppers with snap hinges that have proven to be very reliable. A plastic closure of similar construction, but that does not have a snap hinge, is known from French patent No. FR-2 309 425. The present invention is based on the technical problem of making a generic stopper with a snap hinge, that is both less expensive to produce and safe and easy to use. This technical problem is solved by the present invention as will be described below.
The known closures of the kind referred to above are injection molded in a position open to approximately 180.degree.. The opening to a complete 180.degree. is necessary in order to achieve a simple mold opening without transverse stresses. The inverse shapes of the interior contours of the cap and base portions are situated side by side in one half of the injection mold. The hinges must be chosen so that they allow for an opening of around 180.degree., an opening angle that afterwards is not normally in use at all.